Yale University has encountered rapid growth in two aspects of rodent-based research that require substantial expansion of rodent hazard containment space. First, the use of biohazardous agents is a significant and increasing component of rodent-based at Yale. Research with such agents has increased about 40 percent during the past five years. Most recently, Federal funding for biological hazards has substantially increased which suggests that the emergent trend in this area will continue and likely escalate. Second, the importation of genetically engineered mice (GEM) from investigators at other institutions-a scientifically essential component of contemporary research-requires quarantine and testing prior to releasing then into Yale colonies. Further, Yale is the site for a national metabolic phenotyping core which requires both quarantine and phenotyping. We are projecting to import over 400 cohorts this year subject to quarantine and testing and this number is increasing annually at an average of 18 percent. These two activities are currently packed into dispersed facilities, which are primarily used for housing specific pathogen-free (SPF) mice and are neither large enough in total capacity or configured appropriately for optimal containment safety and efficiency. Yale's rodent census has increased steadily since 1992 and has doubled within the past six years. The use of ventilated racks and, most recently, the opening of a new 57,000 square foot mouse facility, The Anlyan Center (TAG), has enabled decompression of overcrowded mouse1 rooms and consolidation of SPF mice. It has also vacated 10,000 gross square feet of space in an existing mouse holding facility in the Laboratory of Surgery, Obstetrics and Gynecology (LSOG). This application requests funds to help support the renovation for consolidation of housing and procedure space for rodents used in research requiring Biological Safety Level 2 (BL2) agents, chemical and radiologic hazards, quarantine, and phenotyping. The proposed renovation will allow LSOG to be used as an efficient, centralized, biosecure containment facility by converting underutilized storage into critically needed procedure space and by revamping existing, contiguous housing space that is readily adaptable for such use.